PPC: [ic] Change CompareIC to handle JSReceiver instead of JSObject.

Port 0ed08780

Original commit message:
    There's no reason to limit the CompareIC to (known) JSObject instances,
    as all JSReceivers behave the same wrt. abstract and strict equality.
    So remove this historical limitation and track JSReceivers instead.

R=bmeurer@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1506903003

Cr-Commit-Position: refs/heads/master@{#32665}

src/ppc/code-stubs-ppc.cc

@@ -3729,16 +3729,17 @@ void CompareICStub::GenerateStrings(MacroAssembler* masm) {
 }
 
 
-void CompareICStub::GenerateObjects(MacroAssembler* masm) {
-  DCHECK(state() == CompareICState::OBJECT);
+void CompareICStub::GenerateReceivers(MacroAssembler* masm) {
+  DCHECK_EQ(CompareICState::RECEIVER, state());
   Label miss;
   __ and_(r5, r4, r3);
   __ JumpIfSmi(r5, &miss);
 
-  __ CompareObjectType(r3, r5, r5, JS_OBJECT_TYPE);
-  __ bne(&miss);
-  __ CompareObjectType(r4, r5, r5, JS_OBJECT_TYPE);
-  __ bne(&miss);
+  STATIC_ASSERT(LAST_TYPE == LAST_JS_RECEIVER_TYPE);
+  __ CompareObjectType(r3, r5, r5, FIRST_JS_RECEIVER_TYPE);
+  __ blt(&miss);
+  __ CompareObjectType(r4, r5, r5, FIRST_JS_RECEIVER_TYPE);
+  __ blt(&miss);
 
   DCHECK(GetCondition() == eq);
   __ sub(r3, r3, r4);
@@ -3749,7 +3750,7 @@ void CompareICStub::GenerateObjects(MacroAssembler* masm) {
 }
 
 
-void CompareICStub::GenerateKnownObjects(MacroAssembler* masm) {
+void CompareICStub::GenerateKnownReceivers(MacroAssembler* masm) {
   Label miss;
   Handle<WeakCell> cell = Map::WeakCellForMap(known_map_);
   __ and_(r5, r4, r3);